Humidity-sensitive, shape-controllable, and transient zinc-ion batteries based on plasticizing gelatin-silk protein electrolytes

The research and development of transient energy devices used to power implanted electronic is an emerging engineering field that has attracted increasing attention. This device not only requires the material and system design with excellent performance in routine operations but also can be degraded at a controlled rate once a specific task is completed. Herein, we report a transient, high-performance and formable yarn-like zinc-ion battery (ZIB) composed of a smart humidity-sensitive plasticized gelatin-silk fibroin electrolyte film and a dual-yarn electrode structure. This transient energy battery device exhibits a high specific capacity (311.7 mA h g⁻¹) and excellent cycle stability (94.6% capacity retention after 100 cycles) due to the high ionic conductivity. More importantly, the yarn ZIB device also demonstrates superior shape plasticity (high capacity retention of 82.5% after 80 bends) and good biodegradability (fully degraded in 45 days under enzyme digestion). The successful design and fabrication of the ZIB battery system provide new research ideas for the development of transient energy devices in the future and bring new opportunities for multifunctional and green sustainable transient electronic products in the fields of medicine, national defense, flexible wearable, and consumer electronic products.